Now they want to kill you with kindness, not just with heaping piles of artery-choking pastrami and corned beef.

The brass at Manhattan’s iconic Carnegie Deli — which has been dishing out house-cured meat, sour pickles and steaming matzo-ball soup since 1937 — want their famously rude waiters to turn those frowns upside-down.

“We’re trying to warm it up a little,” said new COO Robert Eby, 51.

“Being rude may have been cute with the old Jewish waiters and waitresses in the ’50s and ’60s, but not anymore. Today, it’s all about hospitality and being hospitable,” Eby told The Post.